This application claims priority to Korean Patent Application No. 2002-34624, filed on Jun. 20, 2002, the disclosure of which is incorporated herein by reference.
1. Field of the Invention
The present invention relates to a silicon-containing photoresist composition and a method for patterning a semiconductor device. More particularly, the present invention relates to a silicon-containing negative resist composition suitable for use in a bi-layer resist process, and a method for patterning semiconductor devices using the same.
2. Discussion of the Related Art
As the manufacture of semiconductor devices becomes more complicated and semiconductor devices become more highly integrated, there is a need to form fine patterns. Furthermore, with regard to 1-Gigabit or more semiconductor devices, a pattern size having a design rule of 0.2 μm or less is needed. Therefore, the use of conventional photoresist materials for KrF eximer laser (248 nm) is limited. For this reason, lithography techniques using ArF eximer laser (193 nm) or F2 eximer laser (157 nm), which are shorter-wavelength energy sources than KrF eximer laser, have emerged. Lithography processes using F2 eximer laser (157 nm) need resist materials having a new structure.
However, ArF and F2 resist materials have many problems due to their structural limitations as compared with i-line or KrF resist materials, which include pattern collapse due to the fine pattern size and poor resistance to dry etching. Therefore, there is a need to develop new resist materials and processes therefor.
In a photolithography process for manufacturing highly integrated semiconductor devices, the application of a bi-layer resist (BLR) process improves characteristics such as dry-etching resistance and formation of high aspect ratio patterns.
In the BLR process, binary chemically amplified resists composed of a silicon-containing polymer having in its backbone silicon atom substituents and a photoacid generator, e.g., positive chemically amplified resists, have been widely used. Also, the development of highly sensitive resist materials for BLR processes using a short-wavelength light source has focused on positive chemically amplified resists. However, silicon-containing resist compositions developed to date for BLR processes have strong hydrophobicity and exhibit poor adhesion to the underlying layer. Also, it is difficult to control the amount of silicon to an appropriate level for resist materials.
The use of positive resists is limited in forming isolated patterns for high-speed, high-performance DRAMs. A lithography process for manufacturing 1-Gigabit or more DRAMs necessitates the use of a phase shift mask. In designing phase shift masks, using negative resists is more advantageous than using positive resists. Therefore, a need exists for developing negative resists which are highly transparent with respect to an exposure light source having a short wavelength, and exhibit high resolution and have a high resistance to dry-etching.